Ski GPS

I'm in a panic now, I'm off to recheck

Far cheaper and more accurate:

Making a Clinometer

The following items are needed to make a simple clinometer :


Protractor : The plastic type found in drawing sets and used by Maths departments are fine, but larger ones can be easier to read.
Narrow tube : A thin tube such as the body of a ballpoint pen. This will be the 'sight' mounted on the protractor.
String or thread : About 30cm ( 1 foot) of thin but Strong string.
Weight : Anything small and heavy which can be attached to one end of the string to keep it taught, such as a metal nut or fishing weight.
Glue or sticking tape : To assemble your clinometer. Glue must NOT dissolve in water !

Method

1. Glue or tape one end of the string firmly to the center of the protractor where all the lines meet. This will be half way along its flat base. Make sure that the string can hang down freely when the protractor is held with the flat side at the top.

2. Attach (glue or tape) the 'sight' tube along the straight edge of the protractor.

3. Attach your weight to the free end of the string and check again that the string can move freely as you tilt the protractor up and down.

That's all there is to it. You now have a clinometer which, hopefully, looks something like the one below.

tino_11 wrote:Far cheaper and more accurate:

and for the skier, something I posted before :

& I should also say, you can do this with your ski poles and, a bit of our old favourite, trigonometry

Put one pole vertically in the snow, put the other pole touching and at a right angle to first pole pointing up hill. Now move the horizontal pole down until the uphill end touches the snow.

Now you've a right angled triangle (the 90' is where the poles touch) with the hypotenuse formed by the slope itself. Now just do the maths

Seriously though.... you'll work out that if the horizontal pole is at the top of the vertical pole then you've formed a triangle with equal sides, and you'll remember from school that must mean the slope is 45'. Some other angles are :

1:1/2 ~27'
1:3/4 ~37'
1:1 = 45'

Over 45' and we move the horizontal pole horizontally, when half its length is moved you're looking at around 63'

You can put some tape on your ski poles and/or write on them to remember this as my handy hint of the day

Er...won't this be a different result with different length poles :?:

I mean both poles being the same length, but using varying length poles?

Does that make sense?

Also, how can half of 45 be 27?

an equilateral triangle is an equilateral triangle regardless of the length of the two equal sides, if your poles are 120cm or 300cm the angles are still 45'

half of 45 is 22.5 but this is a tan() function not a linear scale.

and no in answer to your other question ) )

:shock:

ise wrote:an equilateral triangle is an equilateral triangle regardless of the length of the two equal sides, if your poles are 120cm or 300cm the angles are still 45'

half of 45 is 22.5 but this is a tan() function not a linear scale.

and no in answer to your other question ) )

I'm not questioning your maths or the logic, I think it will make sense if I see it done in practice. It's all feeling a bit abstract for me currently )

I wish I never started this thread again, still I like my new toy anyway. :wink: